The present disclosure relates to electrophotographic photosensitive members.
As an electrophotographic photosensitive member included in an image forming apparatus, there has been known an organic photosensitive member containing: a binder resin; a charge generating material; and a hole transport material and an electron transport material as charge transport materials; and so on. Such an organic photosensitive member is advantageous in that it can be produced more easily and have higher degree of freedom in structural design as having more options for materials of the photosensitive member as compared with an inorganic photosensitive member including an inorganic material such as amorphous silicon.
In order for an image forming apparatus including an organic photosensitive member as an electrophotographic photosensitive member to form high-quality images, there is a strong need for the organic photosensitive member to have sufficient photosensitivity. In particular, where the photosensitive member is to be positively charged in use, the photosensitivity of the electron transport material has great impact on the quality of an image to be formed by the image forming apparatus. Accordingly, various electron transport materials capable of enhancing the photosensitivity of the organic photosensitive member have been investigated.